import com.kotlin.lib.Student

fun main() {
    println(4 shl 1)
    println(4 shr 1)

    val student: ArrayList<Student>? = null

    var status = false
    student.isNullOrEmpty().let {
        println("here.${it}")
    }
    println("result:${student.isNullOrEmpty()}")
    println("result:${student?.isNotEmpty()}")
}